HotSpot - captive portal android

All mobile OS just check a web page to decide whether they're behind a captive portal or not. The mechanism is this: GET/POST http://foo.com/bar.html If bar.html == [expected content] > Open Internet If bar.html != [expected content] > Captive Portal If bar.html[status] != SUCCESS > No Network Also, for iOS, you need to have a domain for your Wi-Fi network as it assumes a domainless network without access is a home network and just marks it as No Network instead of Captive Portal. Just make sure to explicitly redirect the following urls to your captive portal with HTTP Success: Android / Chromebook: clients3.google.com clients3.google.com/generate_204 (for  AndroidXRef - KitKat 4.4.4_r1 ) connectivitycheck.android.com connectivitycheck.gstatic.com/generate_204 (for AndroidXRef - Marshmallow 6.0.0_r1) iOS 6: gsp1.apple.com *.akamaitechnologies.com iOS 7: www.appleiphonecell.com www.airport.us *.apple.com.edgekey.net *.akamaiedge.net *.akamaitechnologies.com iOS 8/9: http://www.apple.com/library/test/success.html http://captive.apple.com/hotspot-detect.html Windows ipv6.msftncsi.com www.msftncsi.com Amazon Kindle (Fire) The Amazon Kindle (Fire) makes the following request, and if it cannot be retrieved "... it assumes that the user has to login and throws up a Log In screen.": http://spectrum.s3.amazonaws.com/kindle-wifi/wifistub.html See Also: https://forums.developer.amazon.com/forums/thread.jspa?threadID=834 iOS 8.4 For the latest iOS I had to match all URIs for requests to http://captive.apple.com - not just "/hotspot-detect.html". iOS 8.4 clients are making requests with randomly generated URIs (e.g. "/xmqPyZUv/3r8jTjv8.html" and "/7exN0TV7q0COX0/eKlBU8baU2tape/fjXUzDHBdE6W0O/BGbw7iYU2DVBh1/sVBlx8icYzTTtE.html") in URL requests to the following domains to detect a captive portal: http://captive.apple.com http://www.ibook.info http://www.itools.info http://www.thinkdifferent.us Many vendors have also began to use the User Agent "CaptiveNetworkSupport", though it's not as common as the URL method above. Just check for that UA and always give it your portal page...doesn't work 100% though. I use the URL method and it's been working fine.

fonte:

http://www.magicbluesmoke.org/how-to-disable-googles-captive-portal-detection-and-why-doing-so-closes-a-small-privacy-hole/

https://android.stackexchange.com/questions/139588/captive-portal-detection-causing-phones-to-disconnect-from-wi-fi-in-intranet-env